The present invention relates to electrical elbows and, in particular, the present invention relates to an elbow canister fuseholder that allows for the simple replacement of fuses in electrical elbow applications.
There are several ways of achieving an in-line fuse for underground application. One provides an insulated molded housing where the fuse is inserted, with interference, into rubber housing or is molded into epoxy housing. The disadvantage of the rubber housing is that the fuse changeout procedure is difficult to perform in the field.
Another application is to use an epoxy housing where the fuse is integral to the part, making the housing non-reusable after the fuse opens. A second type of epoxy housing, allows replacement of the fuse, but is large and bulky. In neither case does an epoxy type housing provide direct connection to a cable or apparatus without the use of additional connector components. Further, epoxy housings tend to fragment on failure, expelling hard pieces that can cause damage or injury, unlike rubber housings that split or rupture to release internal pressure, but stay intact.
Another application exists in the use of a dry well canister. This is a holder that requires additional insulation around the outside, such as oil or SF 6 gas. It is typically mounted in a tank filled with this insulating medium. It requires an auxiliary bushing mounted on the tank wall and additional connector components to provide connection between the fuse and the cable.
The present invention eliminates the above difficulties and disadvantages by providing a new elbow canister fuseholder comprising an electrically insulated and shielded housing for placing a fuse in-line between a cable and an electrical apparatus for underground distribution application. An insulating tube is contained within the housing for easy sliding removal of the fuse through an end plug opening such that the elbow is reusable when a fuse is replaced.
In accordance with a preferred arrangement of the invention, an elbow fuseholder comprises a housing including a generally elongate insulative sleeve defining at one end thereof a cable entrance for receipt of a cable therein, and at the opposing end a fuse entrance opening. An elbow interface is joined to the sleeve at an angle and defines a mating interface for electrical connection with an external bushing insert. A fuse is electrically connected at one end thereof to a conductor of a cable received in the sleeve and electrically connected at the other end thereof to the elbow mating interface. An insulative tube is disposed interiorly of the insulative sleeve, and slidably supports the fuse therein. In a particular form of the invention, the elbow fuseholder includes a plug disposed within the sleeve, the plug being detachably connected to the fuse at the elbow interface. As such, the fuse and plug are joined in an assembly that is removable from the tube through the fuse entrance opening.